[PATCH] tools: perf: Report collisions in AUX records

[Suzuki K Poulose]

Just like the other flags in the AUX records, report a summary
of the Collisions if there were any.

Cc: Mike Leach <mike.leach at linaro.org>
Cc: Mathieu Poirier <mathieu.poirier at linaro.org>
Cc: Leo Yan <leo.yan at linaro.org>
Cc: James Clark <james.clark at arm.com>
Cc: Arnaldo Carvalho de Melo <acme at kernel.org>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Jiri Olsa <jolsa at redhat.com>
Cc: linux-perf-users at vger.kernel.org
Cc: Alexander Shishkin <alexander.shishkin at linux.intel.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose at arm.com>
---
 tools/perf/util/events_stats.h | 1 +
 tools/perf/util/session.c      | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/tools/perf/util/events_stats.h b/tools/perf/util/events_stats.h
index 3480bafd414b..1b0006092265 100644
--- a/tools/perf/util/events_stats.h
+++ b/tools/perf/util/events_stats.h
@@ -30,6 +30,7 @@ struct events_stats {
 	u64 total_lost_samples;
 	u64 total_aux_lost;
 	u64 total_aux_partial;
+	u64 total_aux_collision;
 	u64 total_invalid_chains;
 	u32 nr_events[PERF_RECORD_HEADER_MAX];
 	u32 nr_lost_warned;
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 51f727402912..59b6c3fe0d01 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1540,6 +1540,8 @@ static int machines__deliver_event(struct machines *machines,
 				evlist->stats.total_aux_lost += 1;
 			if (event->aux.flags & PERF_AUX_FLAG_PARTIAL)
 				evlist->stats.total_aux_partial += 1;
+			if (event->aux.flags & PERF_AUX_FLAG_COLLISION)
+				evlist->stats.total_aux_collision += 1;
 		}
 		return tool->aux(tool, event, sample, machine);
 	case PERF_RECORD_ITRACE_START:
@@ -1895,6 +1897,13 @@ static void perf_session__warn_about_errors(const struct perf_session *session)
 			    "");
 	}
 
+	if (session->tool->aux == perf_event__process_aux &&
+	    stats->total_aux_collision != 0) {
+		ui__warning("AUX data detected collision  %" PRIu64 " times out of %u!\n\n",
+			    stats->total_aux_collision,
+			    stats->nr_events[PERF_RECORD_AUX]);
+	}
+
 	if (stats->nr_unknown_events != 0) {
 		ui__warning("Found %u unknown events!\n\n"
 			    "Is this an older tool processing a perf.data "
-- 
2.24.1